1. Recommended dietary allowances,1989
2. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Siliconvanadium and Zinc,2001
3. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes,2001
4. Continuing Survey of Food Intakes by Individuals (CSFII) and 1994–96 Diet and Health Knowledge Survey (DHKS). USDA, Beltsville Human Nutrition Research Centre, 1998.
5. Recommended dietary intakes;Beaton,1998